Is there any way to make an HTPC combine three monitor images onto a single 1080p image?

Here's what I'm thinking. I'd like to do some triple-monitor gaming in my HT, with only my HT screen. Typically, the 3-screen resolution of a 3 PC monitor setup would be something like 5760 x 1080. But, of course, I've only got 1920 lines of horizontal resolution. So, question is, is there any way to take the 5760 x 1080 3-screen image and "compress" or "downsample" it to 1920 x 360 (with big black bars on top / bottom) so that all "three screen" images will fit onto my single screen?

Seems like a rather terrible idea to be honest.
I personally have 3x24" 1080p screens for work and I have tried eyefinity in gaming.

Granted this is my opinion, but triple screen gaming is really a smaller niche than 3d gaming.

I have 3 screens and I first spent hours trying to get games going in the large resolution, first fighting the catalyst control panel and then the game engines themselves, and when it worked it worked just barely.
Out of half a dozen games I bothered trying only one worked as what I could call 'intended' and that was half life 2, the rest kinda broke completely or had FOV settings tied directly to the aspect ratio.

360p is actually an even lower resolution than what I used to play doom in., and regular text now a days will not be remotely legible at this resolution.

In short you would be much much much better off just going with regular 1080p, and in my opinion, even if you had 3 screens.

I personally do most of my pc gaming in the hometheater on my 1080p projector, I much prefer 'big' to just 'freaking wide'.

Not sure if you can sim triples on one screen. As others have said it's prob not a good idea. I have a triple1080 setup up but it's only used for sim racing, I didn't like playing anything else on it. It was just very dis orienting using the trriples for FPS and most other games types. I pref using my 30" for all my other gaming.

You do not stop playing because you get old...You get old because you stop playing.

So, some more context, so that it doesn't sound like such a terrible idea : I'm hoping to get iRacing set up on my 12-foot wide, curved HT screen, all on one screen. But, the side screens in iRacing seem to provide pretty useful content. So, I'd like to get them on the single HT screen, somehow.

As an additional aside: The projector is a 4K projector. So, assuming my video card would support 4K, then I could do this in "720p" instead of 360p, albeit at 24 fps.

Just a thought, the idea behind triples for sim racing is to provide a semi surround with the outer two monitors. Unless your curved screen has a decent amount of curvature to get it to the side, then you will be looking a very distorted image.

You do not stop playing because you get old...You get old because you stop playing.

So, some more context, so that it doesn't sound like such a terrible idea : I'm hoping to get iRacing set up on my 12-foot wide, curved HT screen, all on one screen. But, the side screens in iRacing seem to provide pretty useful content. So, I'd like to get them on the single HT screen, somehow.

As an additional aside: The projector is a 4K projector. So, assuming my video card would support 4K, then I could do this in "720p" instead of 360p, albeit at 24 fps.

This suggestion may sound simple. But wait until 2014. And spend $300 on Oculus Rift VR goggles. It will give you a much better and richer racing experience in VR/PC/Mobile. Plus it will be in a perceptual 100"-200" world...in 1080p 60 (minimum) and 3D. Then use your big screen for the other games. But my bet is that when one games on Oculus Rift they will do most of their gaming on it. Until head and Eye fatigue sets in. Just a suggestion. One that could save you a lot of bucks...Be light years better than what you envision doing now...and will be at the root epicenter of what's hot in PC gaming for years to come IMO.

You can check out the Oculus Rift Thread for more information and comments about this breakthrough technology. But it sounds to me like that kind of experience is what you are trying to replicate...with a very compromised approach.

One thing I forgot to mention if you take 3 1080p resolution in portrait mode you will actually get an aspect not to far away from standard 16:9. (1.777)
That is, 3240x1920 27:16 or something (1.6875)

But since you have a 4k display unit, I would quite honestly just go with that (albeit you would probably only be able to get 30hz, not something I would race with but thats me)

I would much rather look into mods that moves the GUI elements you want into a more central position, I have never done much sim racing myself, hell I barely played Gran turismo tbh.
But most simulation games and their fan base are normally rather mod happy so it is more likely you can find something that just moves the Gui elemtens you would want rather than a system to render 3 virtual 1080p screens and downscales the image.